IPVS: stopping backup sync thread 6096 ...
======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc1-syzkaller-00220-g6a325aed130b #0 Not tainted
------------------------------------------------------
syz.4.2221/13610 is trying to acquire lock:
ffffffff900fd448 (rtnl_mutex){+.+.}-{4:4}, at: ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790
but task is already holding lock:
ffff8880543a8aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1b2/0xd50 net/smc/af_smc.c:3073
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
smc_switch_to_fallback+0x35/0xda0 net/smc/af_smc.c:903
smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2781
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:727
__sys_sendto+0x365/0x4c0 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
lock_sock_nested+0x48/0x100 net/core/sock.c:3698
lock_sock include/net/sock.h:1651 [inline]
gtp_encap_enable_socket+0x306/0x630 drivers/net/gtp.c:1676
gtp_encap_enable drivers/net/gtp.c:1720 [inline]
gtp_newlink+0x7bb/0xf80 drivers/net/gtp.c:1513
rtnl_newlink_create+0x39b/0xcb0 net/core/rtnetlink.c:3836
__rtnl_newlink net/core/rtnetlink.c:3953 [inline]
rtnl_newlink+0x18b0/0x1fe0 net/core/rtnetlink.c:4068
rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:727
____sys_sendmsg+0x523/0x860 net/socket.c:2566
___sys_sendmsg net/socket.c:2620 [inline]
__sys_sendmsg+0x271/0x360 net/socket.c:2652
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (rtnl_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
__lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790
inet_release+0x96/0x200 net/ipv4/af_inet.c:422
__sock_release net/socket.c:647 [inline]
sock_release+0x82/0x150 net/socket.c:675
stop_sync_thread+0x4ec/0x5e0 net/netfilter/ipvs/ip_vs_sync.c:2004
do_ip_vs_set_ctl+0x4c1/0xe50 net/netfilter/ipvs/ip_vs_ctl.c:2734
nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
smc_setsockopt+0x25c/0xd50 net/smc/af_smc.c:3081
do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
rtnl_mutex --> sk_lock-AF_INET --> &smc->clcsock_release_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&smc->clcsock_release_lock);
lock(sk_lock-AF_INET);
lock(&smc->clcsock_release_lock);
lock(rtnl_mutex);
*** DEADLOCK ***
1 lock held by syz.4.2221/13610:
#0: ffff8880543a8aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1b2/0xd50 net/smc/af_smc.c:3073
stack backtrace:
CPU: 0 UID: 0 PID: 13610 Comm: syz.4.2221 Not tainted 6.15.0-rc1-syzkaller-00220-g6a325aed130b #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
__lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790
inet_release+0x96/0x200 net/ipv4/af_inet.c:422
__sock_release net/socket.c:647 [inline]
sock_release+0x82/0x150 net/socket.c:675
stop_sync_thread+0x4ec/0x5e0 net/netfilter/ipvs/ip_vs_sync.c:2004
do_ip_vs_set_ctl+0x4c1/0xe50 net/netfilter/ipvs/ip_vs_ctl.c:2734
nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
smc_setsockopt+0x25c/0xd50 net/smc/af_smc.c:3081
do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b7d58d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b7e4cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f2b7d7a5fa0 RCX: 00007f2b7d58d169
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f2b7d60e990 R08: 0000000000000018 R09: 0000000000000000
R10: 0000200000000700 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2b7d7a5fa0 R15: 00007ffcbdc90a08
</TASK>